Earlier, she was global head of strategy - corporate, partnership and content for Google-owned YouTube.
Becket has also held roles with Channel 4 in the UK (head of development), Morgan Stanley, Deloitte and McKinsey.
"We have a strategic focus on growth and building a set of core capabilities that will differentiate us from our competitor set and grow the top line in both our established markets and those that we see playing a bigger role in our future," Spark CEO Jolie Hodson said:
"This new role will further strengthen this growth focus and help to accelerate our transition from traditional telecommunications services to a broader range of digital services that capitalise on the significant investments we are making in emerging technologies like 5G, IoT, and AI.
"Aliza has extensive sector experience driving growth strategies and will bring a unique, international perspective to Spark."
Spark executive team from June 2022
• Chief Executive, Jolie Hodson
• General Counsel, Melissa Anastasiou
• Marketing Director, Matt Bain
• Strategy Director, Aliza Beckett
• Technology Director, Mark Beder
• Corporate Relations and Sustainability Director, Leela Gantman
• Finance Director (CFO), Stefan Knight
• Customer Director, Grant McBeath
• People, Culture, and Ways of Working Director, Heather Polglase
• Product Director, Tessa Tierney